They've been hunted. They've been starved. They've been poisoned. Now, whales are being fried while they're still in the ocean.

Since 2007, research teams have been following whales around the ocean and shooting them with darts. The researchers retrieved skin samples from the darts, performed biopsies, and tallied up the number of sun-damaged cells in the whales' skin. Each year, they found more and more damaged cells.

What's the cause? A thinning ozone layer is letting through more UV light. Whales have no fur to cover them, are too big to hide in the shade, and need too much oxygen to go lower in the water. As a result, they're getting badly sunburned. The phenomenon is especially harsh in tropical latitudes and for light-skinned whales. Whales with darker pigmentation showed less sunburn damage, although they didn't escape it entirely.

The outlook for whale skin is grim, as there doesn't seem much to be done for such large and migratory animals. Zoologist Karina Acevedo-Whitehouse, who worked on the study, explained:

I do not believe we would be able to do very much to reduce the damage to whales caused by sun exposure. However, efforts to mitigate other stressors, such as by reducing contaminants and noise pollution, could be tried and thus aim to reduce their environmental stress levels.

Since there isn't anything that can be done to stop killing whales via in-ocean cookery, we'll have to ease up on killing whales other ways to make up for it.